LONDON (Reuters) - Britain published draft regulations on
Thursday that would make it the first country in the world to
offer "three-parent" fertility treatments to families who want
to avoid passing on incurable diseases to their children.

In a move praised by doctors and but feared by critics who
say the technique will lead to eugenic "designer babies," the
government said the new rules were aimed at preventing
transmission of a serious disease from mother to child and would
be subject to public scrutiny and parliament's approval.

The technique is known as three-parent in vitro
fertilization (IVF) because the offspring would have genes from
a mother, a father and from a female donor.

The British plans come as medical advisers in the United
States began a series of public hearings this week to consider
whether there is scientific justification for allowing human
trials of the technique.

The treatment, currently only at the research stage in
laboratories in Britain and the United States, would for the
first time involve implanting genetically modified embryos into
women.

It is designed to help families with mitochondrial diseases
- incurable conditions passed down the maternal line that affect
around one in 6,500 children worldwide. Mitochondria act as tiny
energy-generating batteries inside cells.

UK AT THE FOREFRONT

Announcing draft plans to allow the technique and launching
a public consultation on them, Britain's chief medical officer
Sally Davies said the proposed move would give women who carry
severe mitochondrial disease the chance to have children without
passing on devastating genetic disorders.

"It would also keep the UK in the forefront of scientific
development in this area," she said in a statement.

Jeremy Farrar, director of the Wellcome Trust international
medical charity, said he was pleased at the decision and urged
the government to "move swiftly so that parliament can debate
the regulations at the earliest opportunity and families
affected by these devastating disorders can begin to benefit."

Scientists are researching several three-parent IVF
techniques.

One being developed at Britain's Newcastle University, known
as pronuclear transfer, swaps DNA between two fertilized human
eggs. Another, called maternal spindle transfer, swaps material
between the mother's egg and a donor egg before fertilization.

A British medical ethics panel that reviewed the potential
new treatments in 2012 decided they were ethical and should go
ahead as long as research shows they are likely to be safe and
effective.

Because Britain is in the vanguard of this research, ethical
concerns, political decisions and scientific advances here are
closely watched around the world - particularly in the United
States.

Britain's public consultation on the draft regulations began
on Thursday and was scheduled to run until May 21, 2014.